<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>轨道轨迹</title>
  <style>
    body {
      background: #000;
      color: #aaa;
      font: 100%/20px helvetica, arial, sans-serif;
    }
    canvas {
      display: block;
      height: 100%;
      width: 100%;
      left: 0;
      margin: 0;
      padding: 0;
      position: absolute;
      top: 0;
    }
    .info {
      font-size: .14px;
      position: absolute;
      top: 0;
      left: 0;
      background: rgba(255, 255, 255, .2);
      color: white;
      padding: 6px 8px;
    }
  </style>
  <script src="../RequestAnimationFrame.js"></script>
</head>
<body>
  <canvas id="c"></canvas>
  <div class="info">点击或按住拖动添加更多粒子</div>
<script src="./index.js"></script>
</body>
</html>